Water-Side economizers are here to stay in the northern climates. Using the cooling tower to create cold water and transferring that temperature to the chilled water …
Free Cooling Heat Exchangers (Part One)
The ASHRAE young engineers heard about the free cooling system in the recent tour of the DTE Vantage Dearborn Central Energy Plant. The free cooling …
Hydronic System Design – High Delta T Can Improve Boiler Efficiency (Part 2 of 4)
How can you increase the operating efficiency of your condensing boiler heating system? This question was raised in the last R. L. Deppmann Monday Morning …
Ice Rink Cooling System – Commissioning the Glycol Expansion Tank
A customer recently called us about an unusual occurrence in a closed hydronic cooling system for an ice rink. The system was filled using a …
Constant Speed 2-Way Control vs. Variable Speed Pumps for Heating and Cooling Coils (Part 2)
An engineer asked a question about using a variable speed pump for air temperature control in lieu of a two-way control valve. What are the …
Constant Speed 2-Way Control vs. Variable Speed Pumps for Heating and Cooling Coils (Part 1)
An engineer asked a question about using variable speed pumps for air temperature control in lieu of a two-way control valve. The question clearly makes you …
Hydronic Primary-Secondary Piping – How Important are the Two Close Tees?
Every year we get questions about the importance of primary-secondary piping rules around boilers and coils. Recently, I also received a call about using a …
Solving Minimum Flow in a Primary Variable System (Part 3)
The engineer is aware of the importance of minimum flow to the pumps in hydronic systems. The R. L. Deppmann Monday Morning Minutes Part 1 …
Minimum Flow in Variable Speed Pumps for Building Hydronic HVAC Systems (Part 2)
The HVAC engineer designing a hydronic system understands the need to protect the circulating pumps from a dead head or no flow condition. This week, …
Variable Speed Chilled Water Systems: Demand Reset
There are multiple methods to vary pump speed in HVAC chilled water systems. A common method is the use of a differential pressure transmitter at …